Transducers convert signals from one domain to another and are often used in sensors. One common sensor with a transducer that is seen in everyday life is a microphone that converts sound waves to electrical signals.
Microelectromechanical system (MEMS) based sensors include a family of transducers produced using micromachining techniques. MEMS, such as a MEMS microphone, gather information from the environment by measuring the change of physical state in the transducer and transferring the signal to be processed by the electronics, which are connected to the MEMS sensor. MEMS devices may be manufactured using micromachining fabrication techniques similar to those used for integrated circuits.
MEMS devices may be designed to function as oscillators, resonators, accelerometers, gyroscopes, pressure sensors, microphones, micro-mirrors. Many MEMS devices use capacitive sensing techniques for transducing the physical phenomenon into electrical signals. In such applications, the capacitance change in the sensor is converted to a voltage signal using interface circuits. However, the design of these interface circuits may become challenging when miniaturizing sensors in the presence of parasitic effects. For example, the presence of a coupled parasitic capacitance may reduce the effective gain of the sensor, that combined with the small size of a MEMS sensor may cause the device to be more easily affected by mechanical or electrical noise.